Search PubMed⌕ Search

Biomedical subjects

J Drescher

Publications and source records attributed to J Drescher.

At least 73 records · Page 4Linked to original sources
PubMed1976

Simultaneous determination of influenza virus antihemagglutinin and antineuraminidase antibodies by means of the combined photometric ACU method I. conduct of test.

A modification of the photometric ACU (antibody concentration unit) method designated as combined ACU test is described by means of which the titers of both antihemagglutinin (AH) and antineuraminidase (AN) antibodies can be simultaneously determined, using intact homologous influenza virus. In addition, the constants describing the reactions of AH and AN antibodies with their antigens can be obtained. These constants were determined for a series of H2M2 and H3M2 influenza virus strains. This paper gives a detailed description of the conduct of test. The sensitivity and accuracy of AH antibody titration by means of the combinated ACU test was found to be the same as achieved by means of the original ACU test. The same conclusion was reached when comparing the titration of AN antibodies by means of the combined ACU test and of a modified ACU test which, in turn, has been found to be more sensitive and accurate than is AN antibody titration by the enzyme inhibition test. However, the sensitivity of AN antibody titration by the combined ACU test was found to decrease progressively as the ratio of AH to AN antibodies exceeded certain limits.

Antibodies, Viral↗
PubMed1976

Kinetics of reactions of antihemagglutinin and antineuraminidase antibodies with H2N2 and H3N2 influenza virus strains and description of a modification of the photometric ACU method for titration of antineuraminidase antibodies.

The isotherms describing the reactions of selected H2N2 and H3N2 virus strains with antihemagglutinin (AH) and antineuraminidase (AN) antibodies were established by use of a photometric hemagglutination inhibition test [antibody concentration unit (ACU) method]. It was found that the AN antibody isotherms had significantly higher values of the constant 1/N than did the AH antibody isotherms. This finding confirms for further virus strains the conclusion that the photometric ACU method can discriminate objectively between AN and AH antibodies. The results obtained when determining by use of the photometric ACU method the kinetics of reactions of AN antibodies oriented to A/Bel (HO)-A/Sing (N2) virus with the neuraminidases of H2N2 and H3N2 strains, and vice versa, indicated that the N2 neuraminidases of the test strains could be divided into the following groups: One group comprising the strains A/Sing/1/57 and A/AA/1/65, a second comprising the strains A/Hong Kong/1/68 and A/England/42/72 and a third represented by A/Port Chalmers/1/73. This finding indicated progressive antigenic variation of the neuraminidases of the strains tested. A modification of the photometric ACU method for the titration of AN antibodies oriented to N2 strains has been developed. The modified technique was found to be more sensitive and accurate than was AN antibody titration by means of enzyme inhibition and HI pattern test.

Animals↗
PubMed1976

Production of highly cross-reactive hemagglutination-inhibiting influenza antibodies in ferrets.

Ferrets were sequentially infected at time intervals of 3 weeks with different influenza virus A strains. It was found that secondary infection can result in the appearance of antibodies highly cross-reacting with a virus strain closely related to the strain of first infection. Such highly cross-reacting antibodies were designated as HCR antibodies. Evidence is presented that HCR antibodies were not antineuraminidase antibodies and, in addition, were not specifically oriented to the strain with which the crossing was observed. When using time intervals of 3 weeks between infections, no increase after secondary infection of antibodies oriented to the strain of first infection was recorded. However, when time intervals of 4 to 5 months between infections were used, secondary infections resulted in an increase of antibodies oriented to the strain of first infection ("original antigenic sin") but not in the appearance of HCR antibodies. In addition, antibodies combining specifically with both infecting strains, designated as doubly specific antibodies, were found. Thus, the conclusion was reached that the original antigenic sin phenomenon and the appearance of HCR antibodies are mutually exclusive events.

Animals↗
PubMed1976

Influence of vaccination with A/PR 8/34 (HO-N1) influenza virus on the oncogenic activity of polyoma virus in newborn Wistar rats.

Vaccination with the A/PR 8/34 (HO N1) strain of influenza virus can decrease significantly the oncogenic activity of polyomavirus in newborn Wistar rats. This effect was regularly observed when animals were vaccinated with 24 hr after birth, whereas vaccinations performed on Days 3 and 10 failed to influence the oncogenic potential of polyoma virus. In 3 series of experiments, influenza virus vaccination resulted in sigificantly decreased tumor rates, and, in a 4th series, in reduced tumor growth only. Heat inactivation of influenza virus failed to abolish its influence on the oncogenicity of polyoma virus. In most of the experiments, the antibody response to influenza virus was enhanced by inoculation of animals with polyoma virus. In contrast, polyoma virus antibody titers were, in some experiments, decreased, and, in others, not influenced by vaccination with influenza virus.

Animals↗
PubMed1974

Kinetics of inhibition of influenza virus hemagglutination by homologous antihemagglutinin and antineuraminidase antibodies as measured by means of the photometric antibody concentration unit method.

The kinetics of the reactions of antihemagglutinin (AH) and antineuraminidase (AN) antibodies with homologous influenza virus were examined by use of a photometric hemagglutination inhibition test (antibody concentration unit [ACU] test). The following results were obtained. (i) The isotherms describing the reaction of AN antibodies with homologous virus were found to have much steeper slopes than did the corresponding AH antibody isotherm. This finding indicates that the photometric ACU method can discriminate objectively between AH and AN antibodies. (ii) The reaction of mixtures of AH and AN antibodies with homologous virus was examined and found that AH antibodies combine with virus independently from the presence of AN antibodies, whereas AH antibodies were found to reduce greatly the measurable degree of hemagglutination inhibition by AN antibodies. (iii) A formula was developed and experimentally confirmed by means of which the binding of virus by mixtures of AH and AN antibodies can be predicted. Thereby, the influence of the relative concentration of AH and AN antibodies on the establishing of isotherms and on their subsequent use for antibody titration by means of the photometric ACU method was investigated. It was found that the procedure routinely employed for establishing isotherms yielded data reflecting the reaction of AH antibodies only. As a consequence, the use of these isotherms will identify AH antibodies.

Antibodies, Viral↗
PubMed1973

Influence of histones on the antibody response in guinea pigs to vaccination with A-Aichi-2-68 (H3 N2) influenza virus.

The influence of total, F1, and F3 histones on the primary antibody response in guinea pigs to vaccination with influenza virus A/2/Aichi/2/68 (H3 N2) was investigated. It was found that histones can greatly reduce the immunoglobulin (Ig) M and, to a smaller degree, the IgG antibody response. The immunosuppressive effect of histones was found to depend critically on the dose of virus used for vaccination, on the type and dose of histones, and on the schedule of histone application.

Animals↗